For nearly 200 years, the U.S. Government has been in the business of defining, maintaining, and providing access to geodetic datums. However, for all but the last 20 years, the definition and realization of those datums has been through very similar observational techniques using passive marks in the ground. The advent of space geodetic techniques has allowed the National Geodetic Survey to approach datum definition and control surveys in an entirely new way. A plan is being established which will allow future datums to be defined through 4-dimensional coordinates on continuously operating GNSS reference stations (CORS) and an accurate gravimetric geoid, thus effectively minimizing the need for passive survey marks in the ground.
SaLIS is a scientific journal devoted to reporting research and new work conducted to advance geodetic surveying, land surveying, large-scale mapping, and geographic information systems designed to advance the development and management of the cadastral parcel data layer and other land information applications. SaLIS publishes research articles, technical papers, technical notes, papers on the current state of surveying education, surveying history, book reviews, and current literature reviews. Every four years, the journal publishes the U.S. Report to the International Federation of Surveyors (FIG). The Proceedings of the Surveying Teachers Conference are published bi-annually.